I want to get TaxNumber in Cert Token

I want to get TaxNumber in Cert Token. This Picture in Subject
2.5.4.97 =0105546018274
In Code :-
TElX509Certificate Cert = _PKCS11CertStorage.get_Certificates(i);
Cert.SubjectName. It' not have value "0105546018274"

You need to inspect OIDs and Values of SubjectRDN property of the certificate. OIDs are integer. If you know only the OID text as on the screenshot, you can convert it to binary using StrToOID function from SBConstants namespace . This function will give you the binary array, which you can use for comparing Certificate.SubjectRDN.get_OIDs(x) with it.

Once you find the index of your needed OID, use this index to read Certificate.SubjectRDN.Values property. That value also will be binary , and its contents are application-specific (we can't know, how to treat it, so we give it away in binary).